Individuals with secondary progressive multiple sclerosis (SPMS) experience significant impairments in ambulation leading to use of canes, walkers, and ultimately wheelchairs. Treatment attempts for progressive MS have been disappointing. No therapeutic intervention has been shown to modulate disability in patients with SPMS.
Functional Electrical Stimulation (FES) cycling has been shown to have multiple primary medical benefits including: increased muscle mass, improvements in bone density, enhanced cardiovascular function, improved bowel function, decreased spasticity and reductions in bladder infection rate. More importantly FES may modulate the inflammatory CNS environment in progressive MS.
There is very limited clinical data available on the use of FES cycling in MS. A pilot trial with 12 MS patients who underwent FES cycling (3 sessions/week for 2 weeks) demonstrated improved spasticity but failed to show improvement in strength and walking speed. Long term FES bracing (3-12 months) for foot drop has been shown to increase strength and walking speed suggesting that it strengthens activation of motor cortical areas and their residual descending connections in patients with MS. In a recent small pilot study progressive MS patients using FES demonstrated improvements on a broad array of functional and neurological outcome measures including gait, upper extremity dexterity, and quality of life. Further, analysis of cerebrospinal fluid before FES and 3 months after initiating FES cycling revealed an enhanced neural repair program (increased CSF TGF-β3) and a reduced inflammatory environment within the CNS (decreased Interferon-γ, IL-7, IL-8).
The broad objective of this study is to determine if FES cycling improves walking in subjects with SPMS. We are proposing a novel, and easy to implement intervention strategy of FES cycling to help improve gait function in individuals with SPMS. A successful outcome on a larger SPMS population would have significant impact towards changing MS clinical care. FES is easily transferable to clinical practice and could potentially ameliorate other complications associated with SPMS such as spasticity, mood and fatigue reducing the burden of health care cost. In addition, we will gain a better understanding of the mechanisms underlying these changes that could be used to design new therapeutic strategies.